Short Problem Definition:

You have been asked to help study the population of birds migrating across the continent. Each type of bird you are interested in will be identified by an integer value. Each time a particular kind of bird is spotted, its id number will be added to your array of sightings. You would like to be able to find out which type of bird is most common given a list of sightings. Your task is to print the type number of that bird and if two or more types of birds are equally common, choose the type with the smallest ID number.

Short Problem Definition:

The member states of the UN are planning to send 2 people to the moon. They want them to be from different countries. You will be given a list of pairs of astronaut ID’s. Each pair is made of astronauts from the same country. Determine how many pairs of astronauts from different countries they can choose from.

Short Problem Definition:

A left rotation operation on an array shifts each of the array’s elements 1 unit to the left. For example, if 2 left rotations are performed on array [1,2,3,4,5], then the array would become [3,4,5,1,2].

Short Problem Definition:

Maria plays college basketball and wants to go pro. Each season she maintains a record of her play. She tabulates the number of times she breaks her season record for most points and least points in a game. Points scored in the first game establish her record for the season, and she begins counting from there.

Link

Complexity:

time complexity is O(A* (N+M))

space complexity is O(1)

Execution:

This challenge could also be solved using the Greatest Common Divisor. Given that the range of values is only [1,100], it is safe to assume that the naive solution will terminate within the time limit.

Short Problem Definition:

The member states of the UN are planning to send 2 people to the moon. They want them to be from different countries. You will be given a list of pairs of astronaut ID’s. Each pair is made of astronauts from the same country. Determine how many pairs of astronauts from different countries they can choose from.

Link

Complexity:

time complexity is O(a(N))

space complexity is O(N)

Execution:

The algorithm has two parts. Part one calculates the size of all countries with the use of Union-Find. Both operations on the data structure take O log-star time. The second part derives the number of all pairs based on country sizes. That algorithm is very similar to Handshakes.

Short Problem Definition:

Sam’s house has an apple tree and an orange tree that yield an abundance of fruit. In the diagram below, the red region denotes his house, where s is the start point, and i is the endpoint. The apple tree is to the left of his house, and the orange tree is to its right. You can assume the trees are located on a single point, where the apple tree is at point a, and the orange tree is at point b.

Short Problem Definition:

Given five positive integers, find the minimum and maximum values that can be calculated by summing exactly four of the five integers. Then print the respective minimum and maximum values as a single line of two space-separated long integers.